*[http://people.redhat.com/berrange/systemtap/bootprobe/ Bootprobe] - a set of [[System Tap]] scripts for analyzing system bootup.

*[http://people.redhat.com/berrange/systemtap/bootprobe/ Bootprobe] - a set of [[System Tap]] scripts for analyzing system bootup.

* and, let us not forget: "cat /proc/uptime"

* and, let us not forget: "cat /proc/uptime"

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+

[ FIXTHIS - should mention (and publish) sstream here ]

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[ FIXTHIS - should also mention initcall_debug (kernel command line option) here - it shows driver init times for many drivers]

=== Technologies and Techniques for Reducing Boot Time ===

=== Technologies and Techniques for Reducing Boot Time ===

Revision as of 19:40, 17 June 2008

Boot Time includes topics such as Boot Time measurement, Boot Time reduction, and Boot Time analysis. Boot Time directly impacts the first perception an end user has of a consumer electronic product. Regardless of how attractive or well designed a consumer electronic device is, the time required to move the device from off to an interactive, usable state is critical to obtaining a positive end user experience. Turning on a device is Use Case #1.

Technology/Project Pages

The following are individual pages with information about various technologies relevant to improving Boot Time for Linux. Some of these describe local patches available on this site. Others point to projects or patches maintained elsewhere.

Measuring Boot-up Time

Printk Times - simple system for showing timing information for each printk.

Bootchart - a tool for performance analysis and visualization of the Linux boot process. Resource utilization and process information are collected during the user-space portion of the boot process and are later rendered in a PNG, SVG or EPS encoded chart.

in progress - Boot-up Time Reduction Howto - this is a project to catalog existing boot-up time reduction techniques. Work on this project is under way. The wiki will serve as the primary repository of information gathered for this project.

Additional Projects/Mailing Lists/Resources

Kexec

Kexec is a system which allows a system to be rebooted without going through BIOS. That is, a Linux kernel can directly boot into another Linux kernel, without going through firmware. See the white paper at: kexec.pdf